Couchx

CouchDB Adapter for Ecto3.

The Adapter supports 1 main Repo, but also dynamic repos where you can querie on multiple Dbs with a dynamic supervisor.

The supported functions in this version are:

Repo.get Struct, doc_id
Repo.all from doc in Struct, where: doc._id in ^doc_ids_list
Repo.all from doc in Struct, where: doc.field == ^field
Repo.insert Struct, doc
Repo.delete Struct, %{_id: doc_id}
Repo.update changeset

It adds a simple way to execute JS view queries with:

  def query(name, design, view_map, key, opts \\ []) do
    {adapter, meta} = Ecto.Repo.Registry.lookup(name)
    adapter.execute(:view, meta, design, view_map, key, opts)
  end

Not ideal, so open to suggestions here.

Mango support

Currently support for mango is limited to do queries on single property, on previously created indexes. The selector is a map with the type property preset to the model namespace, such as:

%{
  selector: %{
    type: "user",
    email: "email@email.com"
  }
}

This will be the query generated by:

import Ecto.Query

Repo.all from u in User, where: u.email == "email@email.com"

It will also work with:

import Ecto.Query

email = "email@email.com"
Repo.all from u in User, where: u.email == ^email

Mango Index

Couchx have a couple of tasks to handle database indexing:

$ mix couchx.gen.mango_index -r MyApp.Repo -n my-mango-index -f name,email

This command will generate a index file on priv/my_app/repo/index/my-mango-index.exs It rely on repos declared under config.exs

import Config

config :my_app, ecto_repos: ["repo", "custom_repo"]
...

And build a file with contents such as:

defmodule MyApp.Repo.Index.MyMangoIndex do
  use Couchx.MangoIndex, repo_name: MyApp.Repo

  def up do
    create_index "my-mango-index" do
      %{fields: ["name", "email"]}
    end
  end

  def down do
    drop_index("my-mango-index")
  end

This file will be executed with

$ mix couchx.mango_index

which will persist the index document in the database defined by the repo. And if you want to remove the index you can call:

$ mix couch.mango_index.down -r MyApp.Repo, -n my-mango-index

TODO:

• Repo.insert_all
• Repo.delete_all
• Bulk doc updates
• Better error handling
• More Mango Queries
• A better view query pattern
• Auto indexing requested JS queries
• JS view index management
• Add tests

Installation

The package can be installed by adding couchx to your list of dependencies in mix.exs:

def deps do
  [
    {:couchx, "~> 0.1.0"}
  ]
end

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/couchx.